Note: Descriptions are shown in the official language in which they were submitted.
CA 02236610 1999-02-08
FIELD OF THE INVENTION
3
a The present invention relates generally to appliances, and more particularly
to an
s improved design for a caster foot assembly for an appliance.
6
7
BACKGROUND OF T1HE INVENTION
9
i o Conventional home appliances such as wet/dry vacuums have used a caster
foot
a assembly such as those disclosed in U.S. Patent No. 4,827,564, assigned to
Emerson
iz Electric Co. As shown in Figures 1 and 2, such prior art caster foot
assemblies 2
i3 comprised a body 4, a caster 6 (comprised of a vcrheel 8, caster fork 9,
caster stem 10, and
~a rivet 11) attached to the underside of the body, .a raised ring 12
constructed on the upper
i s surface of the body, and a drum mount 16 at~:ached to the body and
connectable to a
~6 vacuum drum (not shown). Typically, four caster foot assemblies would
appear on the
underside of the vacuum drum so that the wet/dry vacuum could be easily rolled
about the
,s floor. Moreover, this prior art design allowed various vacuum nozzles and
other
i9 accessories accompanying the wet/dry vacuum to be fitted over raised ring
12 to store such
zo nozzles when not in use.
zi While these conventional caster foot assemblies were advantageous in that
zz nozzles and other accessories could be secured to the weddry vacuum when
not in use,
z3 such designs were prone to tipping, in part because the center of gravity
of the wet/dry
za vacuum was raised to accommodate both the raised ring 12 and the caster 6,
as shown in
zs cross-section in Figure 2. Furthermore, it was relatively difficult to
store the nozzles on
z6 the prior art raised ring design because the nozzles had to be slide-fitted
at an angle
z~ almost exactly parallel with the side walls of the raised ring in order to
fit the nozzle over
2s the raised ring 12.
z9 The present invention discloses a caster foot assembly which overcomes
these
3o problems encountered in the prior art.
-1-
H'. 188151(416F01 ~.DOC~
CA 02236610 1999-02-08
z SUMMARY OF TH1? INVENTION
3
a A caster foot assembly for use with an appliance such as a wet/dry vacuum
s comprises a body; at least one vacuum accessory securing post in the body;
and a caster
6 receptacle in the body, wherein the securing post and the caster receptacle
vertically
z overlap within the body to lower the center of gravity of the appliance. A
portion of the
s top surface of the securing post is angled to facilitate the securing of
accessories to the
9 caster foot assembly.
to
1z BRIEF DESCRIPTION O1F THE DRAWINGS
13
is Other aspects and advantages of the present invention will become apparent
upon
is reading the following detailed description and upon reference to the
drawings in which:
)6 Figure 1 shows an isometric view of a prior art caster foot assembly.
o Figure 2 shows a cross-sectional view of the prior art caster foot assembly
of
is Figure 1.
19 Figure 3 shows an isometric view of the disclosed improved caster foot
assembly.
zo Figure 4 shows a cross-sectional view of the disclosed improved caster foot
z1 assembly of Figure 3.
zz Figure 5 shows the same cross-sectional view as Figure 4 and illustrates
how the
z3 disclosed improved caster foot design facilitates accessories attachment to
the assembly.
za Figure 6 shows the same cross-sectional view of the prior art caster foot
assembly
zs of Figure 2 showing the relative difficulty of ~,ecuring an attachment to
the caster foot
z6 assembly.
z~ Figure 7 shows a wet/dry vacuum drum with two of the disclosed improved
caster
2s foot assemblies attached to the vacuum drum, and an accessory secured to
one of the
z9 caster foot assemblies.
-2-
H188151(4I6F01~ DOC)
CA 02236610 2001-08-O1
I _ _
DESCRIPTION OF ILLLISTRaTIVE E~IBODIVIENTS
3
a Figures 3 and 4 show the disclosed improved caster foot assembly 60. Caster
foot
assembly 60 comprises a body 62, a caster receptacle 80, a caster 63
(comprised of a
wheel 66, caster fork 6=l, caster stem 86, and rivet 65) attached within the
caster
receptacle 80, an entrenched ring or annular groove 68 constructed within the
body and
s defining a securing post 70, and a drum mount 72 attached to the body 62 and
connectable
9 to the vacuum drum 90 (see Figure 7). Because the securing post 70 is built
into the body
l0 62 and vertically overlaps with the caster receptacle 80, the accessories
to be press-fitted
II over the securing post 70 will rest closer to the ground. This is
advantageous when
I z compared with prior art designs because it lowers the center of gravity of
the wet/dry
13 vacuum to which accessories have been attached, thus reducing the risk of
inadvertently
tipping the vacuum.
la Moreover, portions of the top surface of securing post 70 are angled in the
Ib disclosed improved caster foot assembly design to define edge 78. This is
advantageous
> > when compared with prior art designs because it is easier to secure the
vacuum
Is accessories to the securing post 70. Specifically, because of the angled
edge 78, a tubular
19 accessory 8~, such as a wet/dry vacuum nozzle, can be easily placed over
the securing
zo post 70 with a greater angle of entry or ''lead-in angle" when compared
with the prior art
z1 designs. As shown in Figure ~, a user wishing to attach an accessory 85 to
the improved
zz caster foot assembly 60 may direct the accessory 85 at a greater angle of
entry 83 with
z3 respect to the substantially vertical side wall of the securing post 70.
Per the disclosed
za design, the bottom ring of accessory 85 may touch the angled edge 78, and
easily slide
z~ down into the entrenched ring or annular groove 68 in order to secure the
accessory 85 to
z6 securing post 70. By comparison, the prior art design, which did not have a
top surface
z~ suitable for angling, required the user wishing to secure an accessory to
direct the accessory
zs 85 at a substantially zero-degree angle of entry, making it harder for the
user to align the
z9 accessory with the substantially vertical side wall of the raised ring.
Thus, as shown in
3o Figure 6, when a large angle of entry is used to try to secure an accessory
to the raised '
_3_ _
CA 02236610 2001-08-O1
i ring 12 of the prior design, the accessory will not slide onto the ring with
the same ease as
z per the disclosed inventive design.
3 The disclosed caster foot assembly 60 is preferably constructed as a single
mold
s injected plastic body into which the body 62, the entrenched ring or annular
groove 68, the
drum mount 72, the caster receptacle 80, and a detent or retaining rib 82 are
formed. A high
density plastic, such as poly-propylene, is a suitable material. The caster 63
is readily
purchasable as an assembly. A suitable caster 63 will include an enlarged nub
84 on the caster
s stem 86 which can be "snapped" across the retaining rib 82 and into the
caster receptacle 80.
Once attached, the greater diameter of nub 84 will ensure that the caster
assembly will not slip
,o back out of the caster receptacle 80, it being held by the smaller diameter
ring formed by the
retaining rib 82. Once attached, the caster stem 86 ofcaster 63 can turn
relatively freely within
,z the caster receptacle 80.
o Figure 7 shows the disclosed caster foot assembly 60 attached to a wet/dry
m vacuum drum 90. Four caster foot assemblies usually appear at equal
distances around
i; the bottom edge of the wet/dry vacuum drum 90, although one of ordinary
skill will
realize that more or less assemblies could also be used. The caster foot
assemblies 60 are
> > connected to the vacuum drum 90 by press-fitting the drum mount 72 into an
is appropriately sized receptacle within the vacuum drum 90 (only a portion of
which being
shown in Figure 7). Figure 7 also show an accessory 85, such as a vacuum
nozzle, which
zo has been attached to the disclosed improved caster foot assembly.
zi The accessories 8~ can be press-fitted onto the securing post 70 as shown
in
zz Figure 5. This can be accomplished by shaping the accessories 85 and the
securing post
23 70 appropriately so that the two can adequately mate. If a press-fitting
arrangement is
z~ used, the bottom of the accessory will not touch the bottom of the
entrenched ring or annular
zs groove 68 when an accessory 85 has been secured to securing post 70. A
press-fitting
z6 arrangement is preferred in large part because an accessory 85 that has
been press-fit onto a
z~ securing post 70 will not "wobble" and should be satisfactorily mounted. Of
course, one of
is ordinary skill will realize that many other mounting arrangements are
possible, including
z9 a slip-fitted arrangement where the bottom of the accessory 85 will touch
the bottom of the
3o entrenched ring or annular groove 68.
__
CA 02236610 2001-08-O1
i Those skilled in the art who now have the benefit of the present disclosure
will
z appreciate that the present invention may take many forms and embodiments
and have
3 many uses. For example, the present invention can be used in conjunction
with
a appliances other than wet/dry vacuums and can be used to store or secure
more than the
s accessories to be used with the appliance. Also, one of ordinary skill will
realize that
while the use of an entrenched ring or annular groove 68 has been disclosed as
a way
of defining securing post 70, the securing post 70 can be defined in any
number of
ways consistent with the disclosed invention.
9 For example, the excess body material surrounding entrenched ring or annular
groove 68
~o is not necessary to define the securing post 70 and may be eliminated,
although it is currently
i ~ preferred for reasons of mechanical stability. Even when such excess
material is
n eliminated, the inventive advantage of a lowered center of gravity
facilitated by caster
i3 receptacle/securing post vertical overlap can still be realized.
is ~ The disclosed improved caster foot assembly may be modified to irLclude
more
is than one securing post for the attachment of multiple accessories to a
single caster foot
i6 assembly.
o Furthermore, while the side walls and the top surface of the securing post
as
is disclosed form a roughly cylindrical shape, part of the top surface of the
securing post
i9 may also be recessed such that the top surface of the securing post defines
a ring structure
zo similar to the prior art, although of sufficient thickness to be angled. In
this embodiment,
z~ partially recessed top surface would define a second securing post within
the first
zz securing post 70, and the caster receptacle 80 would be contained within
and would
z3 vertically overlap with the second securing post. Such a structure would
have the
z.s advantage of providing two concentric securing posts which could
accommodate
is accessories of different diameters, and both of which could be angled to
provide easier
z6 accessory mounting.
n Moreover, while it is presently preferred to design the improved caster foot
za assembly with the caster receptacle directly in the center of the securing
post, as shown in
z9 Figure 4, . the advantages of lowered center of gravity facilitated by
caster
3o receptacle/securing post vertical overlap can be realized even when the
caster receptacle
_5_ _ _
CA 02236610 1999-02-08
( is not centered with respect to the securing post, and even when the caster
receptacle is
formed outside the area defined by the securing post.
3 It is intended that the embodiments described herein should be illustrative
only,
a and not limiting with respect to the scope of the; present invention.
Rather, it is intended
s that the invention encompass all modifications, equivalents and alternatives
falling within
the spirit and scope of the invention as defined b~y the appended claims.
H' 188151(416F01! DOC)
